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Gear / Technical Help => Post-Processing, Computer / Streaming / Internet Devices & Related Activity => Topic started by: travelinbeat on February 05, 2010, 03:09:41 AM

Title: Remove noise from boost in post
Post by: travelinbeat on February 05, 2010, 03:09:41 AM
I recorded the Magnetic Fields tonight, a band who only plays acoustic when they play live, and always plays very quietly, though frequently too quietly for the rooms (theaters) they play.  Anyways.  Here's my problem.  I recorded using CA-14's > CA-9100 (all the way to +20db) > R-09HR on 24/96 into the Mic-In on love level Mic Gain, at level 30 on the device.  Even with this, I've still found that if I envelope the otherwise-deafening applause in between songs (and the odd clap during a song), I still add about +24db in order to normalize the real "meat" (songs) of the performance.  Obviously, this adds the hell out of some really ugly noise.  Wondering if anyone may be willing / able to walk me through some suggestions towards how I might remove this horrible hiss, while keeping my show at conveniently listenable levels. 

I've uploaded a sample song in 24/96 level 8 flac, and it's just under 3 mins long.  You'll hear the hiss right off the bat,then it gets a little less noticeable once the music picks up.  The only edits I've made are the fade in / out, the enveloping of the audience applause at the end, and one clap turned down at about 2:25.

Thanks a ton for any and all help-- I'd love to get this recording scrubbed up and sounding good!
http://www.megaupload.com/?d=CDMVP6KX
Title: Re: Remove noise from boost in post
Post by: bgreen on February 05, 2010, 07:47:15 AM
The only program I really like for minute bits of NR is Algorithmyx but to be perfectly honest, without making a marked decline in the fidelity, I can't really get it to where I would be happy with it. You could certainly attentuate it a bit  but to be honest, when you have hiss like that, there really is no magic plugin/solution to make it better without degrading the sound more than the hiss does. Just my 2 cents ;-)

Interesting sounding band, never heard em.

 
Title: Re: Remove noise from boost in post
Post by: travelinbeat on February 05, 2010, 12:46:21 PM
Seems odd that after a 9100 that you'd go mic-in and not line-in on R9.  What software do you use?

I set levels on the opener and I was getting virtually no signal line in, so I decided I could try out mic-in and pick up a bit more db going that route.  Software I have Soundforge, Cool Edit, Reaper, Vegas, and iZotope RX.

The only program I really like for minute bits of NR is Algorithmyx but to be perfectly honest, without making a marked decline in the fidelity, I can't really get it to where I would be happy with it.

Thanks for taking a crack at it.

Please let me know if anyone else has anything to offer!
Title: Re: Remove noise from boost in post
Post by: unclelouie on February 05, 2010, 05:55:35 PM
Firstly, I gotta say that I think it's funny that a band called Magnetic Fields only plays acoustic when they play live.

Your initial post makes me think you're dealing with white noise that's spread over the whole audible range, so you're stuck with it. But, when dealing with noise in general, start with a spectrum analysis and try to identify any problematic frequency spikes and notch-filter them out (like 60Hz hum, for example).

It sounds like the root of the problem was the band was too quiet to begin with. Unfortunately the easiest solution to that is to chose your seat wisely and tape with more sensitive mics: there's always next time.

Also, just as a general tip for post-editing: if it's a quiet acoustic show, don't normalize to -0.01db. There's no need to normalize it that loud. Keep the musical peak at something far more reasonable like, oh say -6db or whatever suits your fancy, and use your amplifier to get volume during playback. (I apologize if you know that and have done it already but I'm at work and have nothing to look at the waveform in the file you hyper-linked).

good luck and let us know what you decide to do.
Title: Re: Remove noise from boost in post
Post by: travelinbeat on February 05, 2010, 07:10:21 PM
Louie--  I agree with your assessment that what I'm probably dealing with is white noise throughout (so long as white noise is what I think it is).  I just wish that there were a way to remove it  :'( .  It sounds like it could be a very enjoyable recording if only there wasn't that rotten noise all over it.

I've selected a short period of relative silence in the above linked recording and run spectral analysis, and I'm supplying both an image of the sample and the short (1 second) file itself that was used in the analysis.  Again, this sample is reflective of roughly the same boost I applied to the sample linked above (normalized to -0.1dB, a boost of about 20dB).  Louie I hear what you're saying about the normalization options, and I may well end up cutting back my normalization to something like -6dB, but in the mean time, I'm just trying to get as much info as possible up on this thread so that someone might kick in the door with a million dollar miracle fix.

(http://img.photobucket.com/albums/v337/travelinbeat/noisegraphiccopycopy.jpg)
http://www.megaupload.com/?d=16JXF80X
Title: Re: Remove noise from boost in post
Post by: Gutbucket on February 05, 2010, 07:28:46 PM
..Software I have Soundforge, Cool Edit, Reaper, Vegas, and iZotope RX.

I don't have iZotope RX, but doesn't it include several noise reduction tools (the others may too)?  You may be able to use the segment of noise you posted to 'train' the filter, then tweak how much of the reduction filter is applied, balancing the noise reduction effect against the detrimental aspects of the noise reduction itself.  That's how many noise reduction plug-ins work.  It then becomes a balancing act of how much is good before too much is worse.  You want the tool that does broadband type noise reduction, not one that does impulse type 'pop' or 'click' reduction and not the fancy 'spectral noise removal' tool where you draw a box around the offending clap or cough on the display.

Worth a try.
Title: Re: Remove noise from boost in post
Post by: OOK on February 05, 2010, 08:39:35 PM
Izotope RX is a cool program...but I haven't really figured it out.....its got a huge learning curve......the best one I have found is the WAVS Znoise.....works great!!
Title: Re: Remove noise from boost in post
Post by: travelinbeat on February 05, 2010, 09:31:42 PM
:o HOLY CRAP. 

So iZotope RX is the new "must have" program for all you folks you don't already have it.

Here's a (sightly clipped) wav of this same song, switching back and forth between the before and after of my applying this program's denoise function.  I think this might be the final product (without the switches of course)

http://www.megaupload.com/?d=8BFE0EQZ
Title: Re: Remove noise from boost in post
Post by: unclelouie on February 05, 2010, 10:50:56 PM
I just got home and had a chance to DL your samples.

Firstly - nice job with iZotope RX. There was a boat-load of noise to start and this is defiantly a move in the right direction.

Interestingly enough, I tried out iZotope RX about 9 months ago and wasn't happy with the results. While processing on my computer it sounded great, but when I played it back on my system it just didn't sound right. Ironically, I was trying to do a similar fix for a stealth of Leo Kottke, although I had a much better SNR. You may want to give it a good listen for detail and swelling before finalizing your master.
Title: Re: Remove noise from boost in post
Post by: vanark on February 05, 2010, 10:58:12 PM
I haven't listened to the samples yet, but I had a similar situation a few months ago that I used the Noise Removal tool since I was able to get a section of just hiss to use as the noise filter.  I was happy enough with the results, in fact surprised I could do as well as I did.

http://taperssection.com/index.php?topic=122321.0

I'll have to give your samples a listen.  Always looking for a good editing tool.
Title: Re: Remove noise from boost in post
Post by: travelinbeat on February 06, 2010, 12:03:13 AM
I was trying to do a similar fix for a stealth of Leo Kottke, although I had a much better SNR. You may want to give it a good listen for detail and swelling before finalizing your master.

SNR = Single to Noise Ratio?

I haven't listened to the samples yet, but I had a similar situation a few months ago that I used the Noise Removal tool since I was able to get a section of just hiss to use as the noise filter.  I was happy enough with the results, in fact surprised I could do as well as I did.

http://taperssection.com/index.php?topic=122321.0

I'll have to give your samples a listen.  Always looking for a good editing tool.

Expired links on sendspace-- any chance you still have the originals?  I'd be interested to hear what you could do with the OP sample if you get a chance to tinker a bit.  I'd love to hear an outcome comparable with the one your so proud of so that I might learn the technique for other recordings =)
Title: Re: Remove noise from boost in post
Post by: unclelouie on February 06, 2010, 06:35:58 AM
I was trying to do a similar fix for a stealth of Leo Kottke, although I had a much better SNR. You may want to give it a good listen for detail and swelling before finalizing your master.

SNR = Single to Noise Ratio?


affirmative
Title: Re: Remove noise from boost in post
Post by: travelinbeat on February 11, 2010, 12:24:09 AM
Threw in the towel-- released it, noise and all  :(

http://taperssection.com/index.php?topic=132102.msg1733868#msg1733868
Title: Re: Remove noise from boost in post
Post by: Fatah Ruark (aka MIKE B) on February 11, 2010, 12:48:52 AM
Thanks for taping the Magnetic Fields. Definitely a hard band to tape.

I had the same problem with the levels. I tried and tried to make it sound better and just never succeeded.

Hopefully they play in Colorado again so I can give them a second try.
Title: Re: Remove noise from boost in post
Post by: travelinbeat on February 11, 2010, 12:56:36 AM
Thanks for taping the Magnetic Fields. Definitely a hard band to tape.

I had the same problem with the levels. I tried and tried to make it sound better and just never succeeded.

Hopefully they play in Colorado again so I can give them a second try.

Not to be contradictory, but one of the best tapes I ever pulled was a Magnetic Fields tape from NY 2008.  I stack taped, second row, only one person in front of me.  Came out sounding PERFECT.  Very tough band to tape, but I really couldn't be happier with my NY tape.  Let me know if you're interested and I can reseed it somewhere or something.